The present embodiments relate to a scraper for an applicator to be used in electron radiation therapy.
Radiation with electrons is used in medicine for treatment (e.g., for the treatment of tumors). Electrons are accelerated in linear accelerators. The beam is extended and flattened (e.g., by scatter films). In order to shape the electron beam, collimator units and/or scrapers that laterally delimit the beam are provided in this area.
Electrons, for example, are significantly scattered by air and other materials so that a directional distribution and a spatial distribution of the electrons in the beam is “obliterated.” Consequently, the electron beam is recollimated adjacent to a surface to be irradiated (e.g., the skin of a patient). With electron radiation in the medical field, electron applicators that delimit the dimensions of the electron beam adjacent to the patient in order to reduce the divergence of the beam and, for example, to protect the healthy tissue, are provided.
Electron applicators are known in various designs, common to all of which being that the electron applicators contain at least one scraper (e.g., two or three scrapers).
The design of the applicators and also of the scrapers functioning as collimators is not simply to be considered as a beam-geometric problem, since the scattering has a clear influence on the beam shape. A significant amount of thought was therefore put into the geometric design of applicators and/or consecutive scrapers. One problem, however, is the choice of material for the scrapers, since the beam-physical properties with respect to the field distribution and the lateral leakage radiation of the applicators is also to be considered. Electron applicators that include two or three scrapers made of a homogenous material are therefore used. Certain materials (e.g., metals) are taken into consideration, however, which result in a high weight of the scrapers and thus of the applicators. Brief descriptions of applicators and scrapers in the medical radiation treatment field are found, for example, in an article by L. J. van Battum et al., Phys. Med. Biol. 48 (2003) 2493-2507 or in ICRU Report 35, 2. reprint, 1992, Chapter 3.